When the 8bitDo SN30 Pro + Nintendo Switch is switched on, a common fault is the ghost input. Most often the left but also the right Analog Joystick. I've already bought two, but both are wrong. I replaced the right and left Analog Joysticks with these. Since then there is no ghost input !!! I've been suffering from this bug for at least a year now. I hope I can help someone else.
I bought 2 pieces of 8bitdo sn30 pro plus Nintendo connected. The D-pad does not respond during car play. Because the Analog Handle Joystick gives extra signals. It's the fault of both. Everything has been fine since I exchanged it. The picture shows a bad Analog Handle Joystick.